Riddle Involving Matrices

Ok, so someone showed me a riddle, and it was pretty far fetched, with all kinds of crazy math terminologies that I'd never heard of, but I looked them up and I've progressed a bit through it. But now I'm stuck.

I've taught myself some of the basics about matrices thanks to the internet, and I know what they are. But how does one go about "solving" a matrix?

Here's what I'm stuck at;

"Use the inverse of the 1st 4 Fibonacci numbers (basically, -1, -2, -3, -5) to solve the matrix of the puzzle"

And then I'm given a string of 22 numbers, which is the 'puzzle'. There are no breaks, no ;'s to indicate how it should be broken up into a matrix, nothing. And frankly, I don't even know what it means when it tells me to 'solve' it.

Any one got any idea?

I'm supposed to find an encrypted word at the end of the riddle. When I looked up decrypting matrices, I found:

Matrices can be used to encrypt numerical data. Encryption is done by multiplying the data matrix with a key matrix. **Decryption is done simply by multiplying the encrypted matrix with the inverse of the key.**

(Thanks Wikki)

Is -1, -2, -3, -5 the key? And even so would I need an actual matrix and not a string of numbers to apply it?

You can see the riddle here, http://i84.photobucket.com/albums/k27/Rylla/riddles.png if you're interested.

Thanks. :D